As mentioned above, if you can borrow an endoscope they are a great tool. I was given one as a present and wonder how I ever got by before. They are good for checking the bores and especially for checking the seating of the push-rods when re-fitting. Also, when I bought new Hepolite, sorry I mean taiwanese made pistons I was advised to throw the rings and fit good ones. The rings supplied were very rough. Where abouts ( county will do ) in UK are you.